In conventional, steel-cased firearms, it is common to affix accessory mounting devices directly to the steel casing so that accessories such as, for example, telescopic sights, may be mounted to the firearm. These conventional accessory mounting devices are often very complicated and generally not very durable. Cheaper assemblies such as, for example, extension mounts having clamping jaws that are clamped on a prism rail, also have deficiencies. These extension mounts are not able to be removed and reattached to a firearm in substantially the same position, i.e., a sort of hysteresis occurs in which the shape of the mounting device alters such that the mounting device never assumes the same position it had during the original mounting. When the mounting device does not fit securely on the casing, there is marginal movement, or play. This may seriously affect the accessory of the firearm if the accessory coupled to the mounting device is, for example, a telescopic sight.
Military weapons are even more sensitive to the deficiencies of conventional mounting devices because military assemblies must withstand considerable impacts without the positions of any accessories, mounting devices or other components shifting. For example, with an accessory or mounting device that is mounted on a machine gun, which itself is mounted on an all-terrain vehicle, all components must maintain a stable arrangement during use to ensure proper and reliable continued use. Military assemblies must also transfer and support great forces such as, for example, when the assemblies are connected not only to a relatively light telescopic sight, but also to heavy combat lenses, combat electronics, or to secondary weapons such as grenade launchers. Nevertheless, military assemblies should be simple, cost-effective, compact and readily and conveniently attachable and detachable.
In practicality, assemblies are interfaces that must adhere to strictly defined positions with respect to the arrangement of all of the components of a weapon as well as in general use in all types of devices. The interfaces should also permit simple detachment and reattachment, without ever compromising the defined position assignment in any way.
A known military telescopic sight for sharpshooter guns from the former German Democratic Republic includes two pins attached to the telescopic sight that each correspond to pin sockets on the gun—one in front and one behind the lock. To mount the telescopic sight to the weapon, the telescopic sight is held at a diagonal to the bore axis. Then the front pin is placed in the front socket, and the telescopic sight is then pivoted by 90° until the telescopic sight is parallel to the bore axis. During the rotation, a projection of the front pin engages an undercut in the front socket, and the rear pin locks laterally into the rear socket. For detachment, the activation of a handle on the rear socket releases the rear pin, and then the telescopic sight is again pivoted by 90° such that the telescopic sight can then be lifted out of the front socket.
A major deficiency to this mounting device is that it requires an exact integration of all parts and, thus, is useful in only a very particular case. Requiring such a precise arrangement renders impossible the interchangeability of the telescopic sight or other accessory devices. Furthermore, such a stringent requirement is incompatible with standard manufacturing tolerances of the components of the weapon and the accessory mounting device. In addition, because the pins are separated by a relatively large distance, the sockets are individually attached to the weapon so they can be spaced a distance that will minimize any tolerance. However, this requires the weapon to be massive enough to accommodate these variable components.
Two other pivoting mechanisms are described in German Patent DE 94 06 408 U and U.S. Pat. No. 4,205,473. In the German patent, the pin is pivotable with a pivoting lever and is attached to the mounting device through a center countersunk screw and spring-mounted shaft washer. The U.S. patent also shows a telescopic sight mount, in which the pivotable pin is mounted by means of a rotary screw.